Herpes simplex virus type 2 growth and latency reactivation by cocultivation are inhibited with antisense oligonucleotides complementary to the translation initiation site of the large subunit of ribonucleotide reductase (RR1)

Antisense oligonucleotides complementary to the translation initiation site of the herpes simplex virus type 2 (HSV-2) large subunit of ribonucleotide reductase (RR1) were studied for their ability to inhibit RR1 expression, HSV-2 growth, and its reactivation from latently infected ganglia, The olig omers caused a significant decrease (90%-97% inhibition) in HSV-2 RR1 expre ssion and inhibited HSV-2 growth, with IC50 and IC90 values of 0.11 and 1.0 mu M, respectively. The titers of HSV-2 mutants that are respectively dele ted in the PR (ICP10 Delta PK) or RR (ICP10 Delta RR) domains of RR1 were a lso significantly (500-20,000-fold) decreased, indicating that the antisens e oligomers Interfere with the independent contributions of the two RR1 fun ctions (PK and RR) toward virus growth. Inhibition was sequence specific, a s evidenced by the failure of a two-base mutant (RR1TImU) to inhibit protei n expression and HSV3 growth. Furthermore, the antisense oligomers Inhibite d HSV-2 reactivation by cocultivation of latently infected ganglia (0/8), V irus was reactivated from ganglia cultured without oligomers, in the presen ce of unrelated oligomers (6/8), or in the presence of the two-base mutant RR1TImu (5/8) (p < 0.007 by two-tailed Fisher exact test). HSV3 growth was not inhibited by antisense oligonucleotides complementary to the splice Jun ction of HSV3 immediate-early (IE) pre-mRNA 4 and 5 (IE4,5SA) or the transl ation initiation site of IE mRNA 4 (IE4TI), although the respective HSV-1-s pecific oligomers inhibit HSV-1 growth.